Reverse Polish

Prefix - Infix - Postfix

Infix is standard maths notation, prefix is Polish Notation, and postfix is Reverse Polish Notation. You only need to know about Reverse Polish.

Reverse Polish / Post fix Notation

Reverse Polish Notation is a mathematical notation, in which the operator follows the operands. The result is the removal of the need for parenthesis, because each operation only applies to a fixed number of values. You start from left to right and move to the first operator, this applies to the 2 previous terms.

You then move to the next operator to the right.

For example:

"3 4 +" is equal to 7, 3 + 4 using Infix notation.

"3 4 + 2 *" is equal to 14, (3+4)*2.

Because the operator applies to only two values (in this case) before it, there is no need for parenthesis.